/*模拟实现LINUX进程调度的静态优先级算法和时间片轮转算法引入LINUX调度 */ #include #include #include #include #include #define RUN 1 #define SLEEP 0 #define READY 2 #define DEG_SCHEDULE #define NUM 6 struct OSPCB { int PcbName ; /*进程名字*/ int ReqCount; /*进程执行计数*/ int RunTime;/*进程执行时间数*/ int Prority;/*进程优先级*/ int PcbStatus; /*进程状态*/ int PcbTime;/*进程时间片*/ struct OSPCB* prev; struct OSPCB *next; }; struct ProcessQueue /*模拟CPU调度队列*/ { struct OSPCB *PointerHead; /*指向进程链表头*/ int PcbNumber;/*CPU每次调度计数器*/ }; //static struct CriticalResource //{ // int flag; // char BufferVoice[2000]; //} static int flag; void *Function(int *arg); void InitPcb(struct OSPCB *pcb); int Schedule(struct ProcessQueue *queue); void InheritSchedule(struct OSPCB *pcb); int main(void) { int i,ret; struct OSPCB *pNewPcb,*pNew; struct ProcessQueue *pNewQueue; int a[4][4] = {{1,1,0,1},{2,2,0,2},{3,3,0,3},{4,4,0,4}}; pNewQueue = (struct ProcessQueue *)malloc(sizeof(struct ProcessQueue)); pNewQueue->PointerHead = NULL; pNewQueue->PcbNumber = 0; for(i = 0; i { pNewPcb = (struct OSPCB *)malloc(sizeof(struct OSPCB)); pNewPcb->PcbName = a[i][0]; pNewPcb->ReqCount = a[i][1]; pNewPcb->RunTime = a[i][2]; pNewPcb->Prority = a[i][3]; pNewPcb->PcbStatus = READY; pNewPcb->PcbTime = 3; InitPcb(pNewPcb); if(pNewQueue->PointerHead == NULL) { pNewQueue->PointerHead = pNewPcb; }else{ pNew->next = pNewPcb; pNewPcb->prev = pNew; } pNew = pNewPcb; pNewQueue->PcbNumber++; } #if 0 for(p = pNewQueue->PointerHead; p != NULL; p = p->next) { printf(“process name = %d\n”,p->PcbName); } #endif Schedule(pNewQueue);/*进入进程调度*/ return 0; } void InitPcb(struct OSPCB *pcb) { pcb->prev = NULL; pcb->next = NULL; } int Schedule(struct ProcessQueue *queue) /*进程调度*/ { struct OSPCB *pcb,*CurrRun; int value,SechNumber = 8; pthread_t pthread_id[NUM]; int i = 0; // printf(“%s\n”,__FUNCTION__); for(pcb = queue->PointerHead;pcb !=NULL;pcb = pcb->next) { if(pcb->PcbTime == 0) { pcb->Prority +=4; } pcb->PcbTime = 3; } while(queue->PointerHead != NULL) { for(pcb = queue->PointerHead;pcb !=NULL;pcb = pcb->next) { if(pcb == queue->PointerHead) { CurrRun = pcb; }else{ if(CurrRun->Prority Prority) CurrRun = pcb; } CurrRun->PcbStatus = RUN; } SechNumber–; CurrRun->ReqCount–; CurrRun->PcbTime–; if(i != (CurrRun->PcbName)) { i = CurrRun->PcbName; pthread_create(&pthread_id[i],NULL,(void*)Function,&(CurrRun->PcbName)); } #ifdef DEG_SCHEDULE printf(“present process = %d CurrRun->ReqCount = %d\n”,CurrRun->PcbName,CurrRun->ReqCount); #endif if(CurrRun->PcbTime == 0) { CurrRun->Prority -=4; /*进程惩罚性降优先级处理*/ } if(CurrRun->ReqCount == 0) { if(CurrRun == queue->PointerHead) { queue->PointerHead = CurrRun->next; }else if (CurrRun->next != NULL){ CurrRun->prev->next = CurrRun->next; CurrRun->next->prev = CurrRun->prev; }else{ CurrRun->prev->next = NULL; } // printf(“Run process name = %d Reqcount = %d Sechedule count = %d\n”,CurrRun->PcbName,CurrRun->ReqCount,SechNumber); } if(SechNumber == 0)/*时间片用完重新调度*/ { Schedule(queue); } } return 0; } void SleepProcess(void) { } void DeleteProcess(void) { // return 0; } void *Function(int *arg) /*进程执行函数*/ { int i,count = 0; int PthreadName; struct OSPCB *pNew; pNew = (struct OSPCB *)arg; PthreadName = *(int *)arg; #ifdef DEG_SCHEDULE printf(“Enter the function process %d\n”, PthreadName); #endif while(1) { if(flag == 0) /*访问临界区资源*/ { flag = 1; #ifdef DEG_SCHEDULE printf(“get lcok in process %d\n”, PthreadName); #endif for(i = 0; i { pNew->PcbStatus = SLEEP; sleep(1); } flag = 0;/*释放临界区资源*/ break; }else{ /*自旋直到得到可访问的临界区资源*/ count++; if(count == 5000) { #ifdef DEG_SCHEDULE printf(“flag = %d can not get lock in process name %d\n”,flag,PthreadName); #endif } } } #ifdef DEG_SCHEDULE printf(“flag = %d out process %d\n”, flag,PthreadName); #endif }